Furnace fired with coal dust and like pulverulent fuel



April 6 1926.

E. VOGT ET AL FURNACE FIRED WITH COAL DUST AND LIKE PULYERULENT FUEL Filed Jan. 26, 1926 Patented Apr. 6 1926.

UNITED STATES PATENT OFFICE.

' ERICK v'oermn L nwm'xmcnHor, or BEao scn-eLaDBAcH, onamr.

To all it nun concern:

sg rnmucn FIRED wrrn con. nusr AND 1.11m PULVEBULENT FUEL. I

Application filed January 26, 1928. Serial No. 88,933.:

Be i known that we, Enron VocT and LUDWIG KIRGHHOF, citizens of the German :Re ublic, both residing at Bergisch-Gladand useful Improvements in or Relating to Furnaces Fired with. Coal Dust and like Pul- Germany, have invented certain new verulent Fuel, of whichthe following is a p lo ' zontal or approximately horizontal space for specification.

- The invention relates to furnaces firedwith coal dust and like pulverulent fuel,

such for example, as heating furnaces, weld in furnaces, rolling mill-furnaces, rotary k s,-or the like, of the type having a horithe reception of the material to'be heated,

and a vertical combustion chamber into' which the mixture of fuel dust and air is supplied in a downward direction from the top cover.

According to the present invention in such furnaces. the vertical combustion chamber is completely. open to the'space containing the material to be heated,while the fuel is comletely burnt in the combustion chamber. 11 tlns way the heat'produced in the chamber radiates without loss into the heating the material; therein space thus heatin v satisfactorily by ra iation. In the vertical combustion. chambersused 'hitherto, 'there. v p

k 1s the pipe for-the primary su was either. no 0 ening at all or only a very .narrow one, so t at the heat radiated by the flame reached the. wall of the chamber and wasv reflected back to the opposite wall through, fthe flame. This radiant heat rapidly damaged the walls, whereas with iso that the flame is completely burnt out in the combustion chamber and thesolid or fluid particles fall on to the bottom of the chamer when the flame changes its dlrection and with the powdered fuel.

' turns to the heating space of the furnace.

The solid or fluid particles gathering on the bottom of the chamber can be easily removed therefrom in some wellknown manner.

To ensure the complete combustion of the "dust fuel in the combustion chamber, the

secondary air supplied to the mixture of fuel dust and primary air is preheated in the known way by contact with the walls of the combustion chamber. In this way the Walls of the combustion chamber'are cooled at the same time. The complete combustion in the combustion chamber makes it dosirable, in spite of the considerable reduction of the action of the radiated heat, to

use a large. quantity of cool air. The quantity of cool air employed'is too great for use as the secondary air supply and the excess of air is therefore diverted before entering the burner by adjustable means to. allow'of the supply of secondary air being-adjusted to suit any particular object or circumstances. P r

In the accompanying drawings, a constructional example of such a furnace is shown, v v Figure 1 is a vertical section of thefur nace, and

' Fi ure 2 is a horizontal section through the line 2--2-of'Figure 1.

air into the top of the combustion'c mber ply of a m indicates the inside of the combustion chamber which is completely open to the space n for the reception of the material to be treated. In the walls of the combustion chamber vertical channels a. are formed. which channels are connected tothe p'ress'ureair conduit 6. The air passes through these channels a into channels 0 underneath rtheebottom 0. of the combustion chamber and from thence through the vertical channelsd, .into a collector space 6' in the cover p of the-I1 combustion chamber from :whence they-are f f led through thepipes f and/z to the. burner. A regulating valve'h is fitted'at the point: V where the pipe f, which 'iso chat the top,

leads into the pipe 11. Accor cooled the walls of the combustion chamber,

mg to the setting of this valve k, the air which hasbeen V heated in the channels a and d and has openito the space 'n.

through the pipe 6 to the burner for use as a secondary air supply, whilst the remainder passes out through the opening atthe upper end of the pipe f. This superfluous heated air can however be put to any desired use.

The flame formed in the inner space m of the combustion chamber passes freely into the space n and owing to the bendin required to reach the space n the flame rops ashes and fluid sediment on to the bottom of the combustion chamber, from whence these residues can be removed through the opening w.

If the space n for the reception of the material to be heated is less in diameter than the space m of the combustion chain-1 her, the latter will, of course, be completely Having now particularly described and ascertained the nature of our said invention and in what manner the same is to be performed, wedeclare that what we claim is A furnace of the type described, embodying a vertical combustion chamber and a space to be heated completely open to the said combustion chamber, means for introducing pulverized-fuel into the top of said combustion chamber, means for a primary supply of air into the furnace with the descending fuel, and means for a secondary supply of air, pre-heated, into the said chamber through the fuel inlet and with the primary supply of air, and means for regulating the supply of such pre-heated air, substantially as described.

In testimony whereof we afiix our signatures.

ERICH VOGT. LUDWIG KIROHHOF. 

